Schiavone books showdown with Sharapova

Schiavone, the 2010 Roland Garros winner, improved to 5-2 against Pennetta, who has only recently returned from wrist surgery.

The all-Italian clash was among 16 first-round women's matches on the opening day of the combined ATP Masters and WTA hard court tournament, in which the 32 men's and 32 women's seeds enjoy first-round byes.

Defending champion Victoria Azarenka is the top women's seed.

The Australian Open champion from Belarus arrives at Indian Wells unbeaten in 14 matches this year and in the second round will face the winner of Thursday's match between two-time Indian Wells champion Daniela Hantuchova of Slovakia and France's Stephanie Foretz Gacon.

Other former Indian Wells champions in the women's field are former top-ranked players Caroline Wozniacki of Denmark and Serbians Ana Ivanovic and Jelena Jankovic.

Jankovic will face a tough second-round clash against two-time Grand Slam champion Svetlana Kuznetsova, who needed just 71 minutes to beat Czech Andrea Hlavackova 6-3, 6-1.

Kuznetsova, winner of the 2004 US Open and 2009 French Open, is on the comeback trail after a knee injury that put her on crutches for two months, followed by weeks of rehabilitation that saw her miss every tournament after Wimbledon last year.

Once ranked as high as second in the world, Kuznetsova dropped to 85th but has climbed back to 46th with quarter-final appearances at Sydney and in the Australian Open.

"I'm happy to be back on the court. This is the main thing," said Kuznetsova, who was runner-up at Indian Wells in 2007 and 2008. "Every day I just try the best I can and things are coming along pretty well."

US wild card Maria Sanchez, ranked 112th in the world, defeated Russian Olga Puchkova 6-3, 6-3 to line up a second-round meeting with third-seeded Agnieszka Radwanska of Poland.

World No. 1 Novak Djokovic and defending champion Roger Federer are the top two seeds in a men's field that also includes Scotland's Andy Murray and Spain's Rafael Nadal.

It's the first tournament to feature the "big four" of men's tennis since last year's Wimbledon, and the spotlight will be squarely on Nadal as he plays his fourth tournament -- and his first on hard courts -- since ending a seven-month injury layoff in February.